Three security cameras, C_1, C_2, and C_3, sweep a perimeter on repeating cycles of 4 seconds, 10 seconds, and 15 seconds, respectively. Camera C_1 sweeps on second 1 of its 4-second cycle, C_2 sweeps on second 1 of its 10-second cycle, and C_3 sweeps on second 1 of its 15-second cycle. During a 300-second surveillance window starting at second 1, during